WASHINGTON -- Seventeen states were told by the U.S. Environmental Protection Agency Wednesday they cannot set their own carbon dioxide emissions standards for automobiles.

The rules proposed by California and 16 other states, meant to ratchet down greenhouse gas emissions, are precluded by federal power, EPA Administrator Stephen L. Johnson said. Also, the energy bill President George Bush signed Wednesday made the state standards moot, he said.

"The Bush administration is moving forward with a clear national solution, not a confusing patchwork of state rules," Johnson said at an evening news conference in Washington. "I believe this is a better approach than if individual states were to act alone."

But California Gov. Schwarzenegger said the EPA's ruling would not be the final word on the matter, The New York Times reported. The Republican governor said the states would go to federal court to get it reversed.

"It is disappointing that the federal government is standing in our way and ignoring the will of tens of millions of people across the nation," Schwarzenegger said. "We will continue to fight this battle."